Add --ignore-size flag - fixes #399

fs/config.go

@@ -87,6 +87,7 @@ var (
 	noGzip          = pflag.BoolP("no-gzip-encoding", "", false, "Don't set Accept-Encoding: gzip.")
 	dedupeMode      = pflag.StringP("dedupe-mode", "", "interactive", "Dedupe mode interactive|skip|first|newest|oldest|rename.")
 	maxDepth        = pflag.IntP("max-depth", "", -1, "If set limits the recursion depth to this.")
+	ignoreSize      = pflag.BoolP("ignore-size", "", false, "Ignore size when skipping use mod-time or checksum.")
 	bwLimit         SizeSuffix
 
 	// Key to use for password en/decryption.
@@ -221,6 +222,7 @@ type ConfigInfo struct {
 	NoGzip             bool // Disable compression
 	DedupeMode         DeduplicateMode
 	MaxDepth           int
+	IgnoreSize         bool
 }
 
 // Transport returns an http.RoundTripper with the correct timeouts
@@ -324,6 +326,7 @@ func LoadConfig() {
 	Config.UpdateOlder = *updateOlder
 	Config.NoGzip = *noGzip
 	Config.MaxDepth = *maxDepth
+	Config.IgnoreSize = *ignoreSize
 
 	ConfigPath = *configFile
 
@@ -358,6 +361,10 @@ func LoadConfig() {
 		Config.DeleteDuring = true
 	}
 
+	if Config.IgnoreSize && Config.SizeOnly {
+		log.Fatalf(`Can't use --size-only and --ignore-size together.`)
+	}
+
 	// Load configuration file.
 	var err error
 	ConfigFile, err = loadConfigFile()

fs/operations.go

@@ -95,7 +95,8 @@ func CheckHashes(src, dst Object) (equal bool, hash HashType, err error) {
 //
 // If the src and dst size are different then it is considered to be
 // not equal.  If --size-only is in effect then this is the only check
-// that is done.
+// that is done.  If --ignore-size is in effect then this check is
+// skipped and the files are considered the same size.
 //
 // If the size is the same and the mtime is the same then it is
 // considered to be equal.  This check is skipped if using --checksum.
@@ -108,9 +109,11 @@ func CheckHashes(src, dst Object) (equal bool, hash HashType, err error) {
 // Otherwise the file is considered to be not equal including if there
 // were errors reading info.
 func Equal(src, dst Object) bool {
-	if src.Size() != dst.Size() {
-		Debug(src, "Sizes differ")
-		return false
+	if !Config.IgnoreSize {
+		if src.Size() != dst.Size() {
+			Debug(src, "Sizes differ")
+			return false
+		}
 	}
 	if Config.SizeOnly {
 		Debug(src, "Sizes identical")
@@ -261,7 +264,7 @@ tryAgain:
 	}
 
 	// Verify sizes are the same after transfer
-	if src.Size() != dst.Size() {
+	if !Config.IgnoreSize && src.Size() != dst.Size() {
 		Stats.Error()
 		err = errors.Errorf("corrupted on transfer: sizes differ %d vs %d", src.Size(), dst.Size())
 		ErrorLog(dst, "%s", err)

fs/operations_test.go

@@ -479,6 +479,50 @@ func TestSyncSizeOnly(t *testing.T) {
 	fstest.CheckItems(t, r.fremote, file1)
 }
 
+// Create a file and sync it. Keep the last modified date but change
+// the size.  With --ignore-size we expect nothing to to be
+// transferred on the second sync.
+func TestSyncIgnoreSize(t *testing.T) {
+	r := NewRun(t)
+	defer r.Finalise()
+	fs.Config.IgnoreSize = true
+	defer func() { fs.Config.IgnoreSize = false }()
+
+	file1 := r.WriteFile("ignore-size", "contents", t1)
+	fstest.CheckItems(t, r.flocal, file1)
+
+	fs.Stats.ResetCounters()
+	err := fs.Sync(r.fremote, r.flocal)
+	if err != nil {
+		t.Fatalf("Initial sync failed: %v", err)
+	}
+
+	// We should have transferred exactly one file.
+	if fs.Stats.GetTransfers() != 1 {
+		t.Fatalf("Sync 1: want 1 transfer, got %d", fs.Stats.GetTransfers())
+	}
+
+	fstest.CheckItems(t, r.fremote, file1)
+
+	// Update size but not date of file
+	file2 := r.WriteFile("ignore-size", "longer contents but same date", t1)
+	fstest.CheckItems(t, r.flocal, file2)
+
+	fs.Stats.ResetCounters()
+	err = fs.Sync(r.fremote, r.flocal)
+	if err != nil {
+		t.Fatalf("Sync failed: %v", err)
+	}
+
+	// We should have transferred no files
+	if fs.Stats.GetTransfers() != 0 {
+		t.Fatalf("Sync 2: want 0 transfers, got %d", fs.Stats.GetTransfers())
+	}
+
+	fstest.CheckItems(t, r.flocal, file2)
+	fstest.CheckItems(t, r.fremote, file1)
+}
+
 func TestSyncIgnoreTimes(t *testing.T) {
 	r := NewRun(t)
 	defer r.Finalise()